Comparative anatomy of the male reproductive internal organs of 51 species of bees

Abstract

Anatomia Comparada dos Órgãos do Aparelho Reprodutor Masculino de 51 Espécies de AbelhasRESUMO -A anatomia dos órgãos internos do aparelho reprodutor de machos (ARM) adultos e pupas foi comparada em 51 espécies de abelhas, incluindo representantes de seis famílias. Foram obtidos quatro tipos diferentes de ARM. O tipo I está presente em machos das famílias mais basais (Colletidae, Andrenidae e Halictidae) e é caracterizado por três túbulos seminíferos por testículo, o qual é quase totalmente envolvido pela membrana escrotal. O tipo II é um tipo intermediário entre os tipos I e III e está presente em Mellitidae e Megachilidae, como também em alguns Apidae estudados, sendo caracterizado por possuir dutos deferentes pós-vesiculares fora da membrana escrotal e possuir três ou quatro túbulos seminíferos por testículo, exceto Apis mellifera L., a qual possui secundariamente um número aumentado de túbulos. O tipo III foi achado somente nos Apidae estudados e é caracterizado por apresentar os testículos e dutos genitais (exceto o duto deferente pós-vesicular) encapsulados separadamente, as glândulas acessórias são bem desenvolvidas e o duto ejaculador é calibroso, apresentando fissuras em sua parede externa, as quais podem ocorrer também no tipo II. O tipo IV está presente exclusivamente na tribo Meliponini e é caracterizado pela ausência de glândulas acessórias. PALAVRAS-CHAVE: Glândula acessória, genitália, morfologiaABSTRACT -The anatomy of the internal organs of the male reproductive apparatus (MRA) of adults and pupae was compared among 51 species of bees, including representatives of six families. Four different types of MRA were found. The type I is present in males of the less derived families (Colletidae, Andrenidae, and Halictidae) and is characterized by three seminiferous tubules per testis, which are almost completely enveloped by the scrotal membrane. The type II is an intermediary between types III and I and is present in Melittidae and Megachilidae, as well as in some Apidae studied, being characterized by post-vesicular deferent ducts outside the scrotal membrane and by three or four seminiferous tubules per testis, except for Apis mellifera L., which has a secondarily increased number of tubules. Type III was only found in the Apidae studied and is characterized by separately encapsulated testes and genital ducts (except for the post-vesicular deferent duct). Accessory glands are well developed, and the ejaculatory duct is thickened with fissures in its wall, which may also occur in the type II. Type IV is present exclusively in the tribe Meliponini, and is characterized by the absence of accessory glands.

Morphology of the male reproductive system and spermiogenesis in Hypanthidium foveolatum (Alfken, 1930) (Hymenoptera: Apidae: Megachilinae)

“…The occurrence of 28 tubules per testis in H. foveolatum differ from the pattern of most basal groups that have three tubules per testis, as occurs in Colletinae, Halictinae, Andreninae and even other Megachilinae as occurs in Anthidium manicatum ( Ferreira et al, 2004). In addition, some other bees present four tubules per testis, such as Mellitinae and Apidae s. stricto ( Roig-Alsina and Michener, 1993), with the exception of Apis mellifera with about 250 tubules ( Chapman, 1998).…”

“…According to classification of Ferreira et al (2004), H. foveolatum comprises type I reproductive apparatus, which was also found in most Colletinae, Andreninae and Halictinae. It is characterized by testes, seminal vesicles and deferent ducts totally or almost encapsulated by the scrotal membrane, forming a globular unit.…”

Structural and ultrastructural characterization of male reproductive tracts and spermatozoa in fig wasps of the genus Pegoscapus (Hymenoptera, Chalcidoidea)

“…In fact, the general morphology of the apparatus has been maintained throughout the order Hymenoptera, but the number of testicular tubules per testis varies considerably among hymenopteran groups. The occurrence of three tubules was reported for some bee families ( Ferreira et al, 2004 andAraújo et al, 2005a) whereas other bees present four tubules per testis, such as Mellitidae, some Megachilidae and Apidae s. stricto ( Roig-Alsina andMichener, 1993 andFerreira et al, 2004), with the exception of Apis mellifera with about 250 tubules ( Chapman, 1998). On the other hand, this number varies from 1 to 25 in Formicidae ( Wheeler and Krutzsch, 1992).…”

Morphology of testicular and post-testicular spermatozoa in Microstigmus arlei Richards, 1972 and M. nigrophthalmus Melo, 1992 (Hymenoptera: Apoidea: Pemphredoninae) with phylogenetic consideration

“…The general morphology has been maintained in the order, but the number of testicular follicles varies considerably among minor groups, without obvious phylogenetic indication: in the Aculeata, the occurrence of three testicular follicles, as in Microstigmus, was still reported in other sphecid wasps of the subgenus Trypoxylon (Trypargilum) ( Moreira et al, 2005a) as well as for some bee families (e.g. Andrenidae, Halictidae, some Megachilidae, Apidae sensu stricto Meliponini) ( Ferreira et al, 2004 andAraújo et al, 2005a) and in Vespidae ( Brito et al, 2005 andMoreira et al, 2005b). However, in other bees, as in Mellitidae, some Megachilidae and Apidae sensu stricto, with the exception of Apis mellifera with about 250 follicles ( Chapman, 1998), each testicle presents four follicles ( Roig-Alsina and Michener, 1993 andFerreira et al, 2004).…”

“…Andrenidae, Halictidae, some Megachilidae, Apidae sensu stricto Meliponini) ( Ferreira et al, 2004 andAraújo et al, 2005a) and in Vespidae ( Brito et al, 2005 andMoreira et al, 2005b). However, in other bees, as in Mellitidae, some Megachilidae and Apidae sensu stricto, with the exception of Apis mellifera with about 250 follicles ( Chapman, 1998), each testicle presents four follicles ( Roig-Alsina and Michener, 1993 andFerreira et al, 2004). In Formicidae, this number may vary from 1 to 25 ( Forbes, 1958, Forbes and Do-Van-Quy, 1965, Beck, 1972 In the testicular follicles, the organization in cysts is also a common feature for species of Hymenoptera.…”